ABSTRACT NUMBER: ESOC2026A750 BASELINE CT PERFUSION IMAGING AND CLINICAL OUTCOMES IN MEDIUM-VESSEL OCCLUSION STROKE: A POST HOC ANALYSIS OF THE ORIENTAL-MEVO RANDOMIZED TRIAL

Abstract Background and aims The role of baseline CT perfusion (CTP) imaging for patient selection in medium-vessel occlusion (MeVO) stroke remains uncertain. Methods We performed a post-hoc analysis of the ORIENTAL-MeVO trial comparing patients evaluated with versus without baseline CTP . Functional outcomes at 90 days were assessed using the modified Rankin Scale (mRS), including ordinal shift and binary thresholds. Secondary outcomes included mortality, hemorrhagic complications, angiographic results, neurological status, and health-related quality of life. Multivariable regression models adjusted for baseline covariates. Results Baseline CTP was not associated with improved functional outcomes. The distribution of 90-day mRS scores was similar between groups (median mRS 2 [IQR 1–4] in both), and no significant association was observed for mRS shift after adjustment (OR 1.07, 95% CI 0.79–1.45). Rates of functional independence (mRS 0–2) were comparable (54.6% with CTP vs 50.5% without CTP), as were Barthel Index outcomes and EQ-5D scores. A nominal association with mRS 0–3 in unadjusted analyses was attenuated after multivariable adjustment. In contrast, baseline CTP was independently associated with lower 90-day mortality (7.2% vs 13.9%; adjusted RR 0.57, 95% CI 0.35–0.94). Rates of symptomatic intracranial hemorrhage and angiographic outcomes were similar between groups. Conclusions In this post-hoc analysis of the ORIENTAL-MeVO trial, baseline CTP was not associated with improved functional recovery but was associated with lower mortality without a clear increase in hemorrhagic complications. Prospective studies are needed to define the optimal role of CTP in MeVO stroke triage. Conflict of interest All authors, nothing to disclosure